Scanning switch



Nov. 3, 1970 T, ONG 3,538,269

SCANNING SWITCH Filed July 30, 1968 4 r 4 I l 1 I, I I

BY ROY MILLER ATTORNEY. GERALD F.- BAKER AGENT.

United States Patent 3,538,269 SCANNING SWITCH Ernest T. Long, China Lake, Califi, assignor to the United States of America as represented by the Secretary of the Navy Filed July 30, 1968, Ser. No. 748,838 Int. Cl. Hlllh 19/58 US. Cl. 200-11 7 Claims ABSTRACT OF THE DISCLOSURE A mechanical switch is provided which connects to a plurality of channels simultaneously. The switch comprises a rotary arm carrying a plurality of contacts and a base plate comprising a double circle of fixed contacts. One of the contacts on the rotary arm mates with a contact of the outer circle on the plate and the remaining contacts on the arm mate with contacts on the inner circle. As the arm is moved by one contact increments, an attached mechanical counter indicates the position.

GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION Electronic scanning switches are, of course, available in many forms. Many available switches are capable of scanning multiple input terminals but give only one channel of output. When a need arose for a specialized switch to scan a plurality of input terminals and which would provide multiple output terminals, none could be found.

Thus, the switch according to the present invention is designed to scan a plurality of input terminals in a circular array and, at the same time, makes contact with a plurality of fixed contacts in a second array of output contacts. In the development of this switch, a number of innovations appear which make for simplicity, efficiency and economy in the fabrication of such switches.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a scanning switch according to the invention;

FIG. 2 is a cross sectional view of the switch of FIG. 1 taken along line 22; and

FIG. 3 is a plan view taken along line 3-3 of FIG. 2 with portions broken away for simplicity.

DESCRIPTION OF THE PREFERRED EMBODIMENT The scanning switch shown in FIG. 1 comprises a contact plate 12 fabricated from a sheet of fiber glass, for example, and carrying a double row of contacts 14, 16 in concentric circular array. A switch arm 13 is mounted on a shaft 15 for rotation about the center of the contact array. The contact arm 13 rides on a bushing 40 and two pads 26, 28 of Teflon or the like. The arm 13 may be force-fit onto shaft 15 or may be retained thereon by a clamp 17 held in place in a well known and obvious manner by means of screw 19. The outer end 11 of arm 13 has a number of substantially identical leaf springs 24 fastened to the arms by means of selftapping screws or the like. On the end opposing the fastening screws, each leaf spring 24 carries a contact pin or brush such as 18 and 20 (-FIG. 2). The brush 20 is situated to ride on contacts 16 in base member 12 and the brushes 18 are situated to ride on contacts 14. The two end pins are not contact pins but carry detent cups 30, 32 which fit over successive pins :14 to hold the arm 13 in the desired position. Pins 14 and 16 are, advantageously, steel drive pins frictionally held in holes drilled in fiber glass base member 12.

Arm 13 may be moved manually or may be moved by a power source through gear 21, for example. Movement of arm 13 also causes movement of shaft 25 through gear 23 which meshes with gear 21. Movement of shaft 25 in turn causes movement of shaft 31 of, for example, an odometer type counter 38 through beveled gears 27, 29.

The pins 14, 16 are preferably copper plated and then cadmium plated after installation. This plating not only protects the pins from corrosion but also provides a better surface for soldering the necessary wiring to the lower portions of the pins. Wire leads are also fastened in any well-known manner to all of the spring members 22 except those operating to bias the detent members 30, 32.

In addition to, or in place of, the odometer counter, the position of switch arm 13 may be indicated by placing on the base member 12 a number of radial lines as shown at 34 in FIG. 1. As will be obvious to workers in this field the base 12 may form the cover of a box containing the necessary connecting wiring or may be incorporated as a part of a switch board or the like.

In operation, when arm 13 is moved, the brush 20 moves onto another of pins 16 thus selecting a new input circuit. All of the brushes 18 ride on contact pins 14 and sequentially provide a plurality of output circuits. Where a plurality of contact brushes are required to ride over a like plurality of pins, it has been found desirable to flatten the heads of the pins and cut a guide groove therein to reduce friction.

Although the odometer counter 38 is shown situated inside the circle of contact points, if 360 movement of arm 13 were desired, it is considered obvious that the counter 38 could be situated without the circle or recessed in plate 12.

From the foregoing it will be obvious that the applicant has provided a multicontact, multiposition switch which is capable of selectively changing one or more input circuits and simultaneously providing a plurality of output circuits and which can be easily manufactured from readily obtainable materials without the use of special tools. The switch in use has proven to be easily operated, rugged and dependable.

What is claimed is:

1. A rotary switch comprising a contact plate of insulating material provided with at least one inner row of serially spaced individual contacts arranged in circular array and at least one outer row of individual contacts arranged in circular array;

said circular arrays of contacts being arranged concentrically in said plate around a central point on said plate;

an arm pivoted to said contact plate at said central point and rotatable over said contacts;

at least one outer brush on said arm positioned to contact successive ones of said outer contacts;

a plurality of inner brushes arranged and positioned on said arm along an arc of a circle positioned over said inner contacts;

so that when said outer brushes are moved to a new position on said outer contacts said plurality of inner brushes will be moved to a new position contacting different ones of said inner contacts.

2. Apparatus in accordance with claim 1, wherein means is provided for indicating the position of said contact arm with respect to said contacts.

3. Apparatus in accordance with claim 2, wherein said means for indicating comprises an odometer type counter.

4. Apparatus in accordance with claim 2, wherein said indicating means comprises a radial scale on said plate.

5. Apparatus in accordance with claim 1, wherein said plate is of fiber glass or the like and said contacts comprise steel drive pins.

6. Apparatus in accordance with claim 5, wherein certain of said contact pins have heads flattened and grooved to facilitate movement of the brushes thereover.

7. Apparatus in acocrdance with claim 1 including cup shaped detent means positioned at each end of the arc of said inner brushes to successively engage with said individual contacts.

References Cited UNITED STATES PATENTS McMaster. Handel.

Rhodes.

Lynch et a1. Lieberman et al. 

